Fuel pump for internal-combustion engines



may i5, w23. 11,4559125 EHQ TAR-FRAIS FUEL PUMP FOR INTERNAL COMBUSTION ENGINES Filed July 16. 1921 2 Sheets-Sheet 1 30 his HTTORN EY.

May 15, w23. www5 E. H. TARTRAIS FUEL PUMP FOR INTERNAL COMBUSTION ENGINES v Filed July 16. 1921 2 Shams-Sheet 2 INVENTOR.

Eugne Henri TLrTrais.

Patented May i5, 11923.'

outro spares,

" 'l TARTS, OF SONS-LAFFITTE, FRANCE.

FUEL PUMP FOR INTERNAL-COMBUSTIUN ENGINES.

Application led July 16, 1921. Serial No. 485,233.

To all whom it may concern: l

Be it known that L FUGNE HENRI TanrruArs, citizen of the French Republic, reslding at Maisons-Laffitte, Seine-et-Oise, 1n the Republic of France, have invented new and useful mprovements in Fuel Pumps for internal-Combustion Engines, of which the following is a specification.

This invention relates to improvements 1n pumps which are employed particularly for injection of liquid fuel in internal combustion engines. The invention relates more particularly to the method of regulating the output, and secondarily to lubrloating and to fluid-tight devices which result from the arrangements adopted for eifectlng the said regulation.

The accompanying drawings show by way of example an embodiment of this invention in the case of a two cylinder two-cycle engine. 'llwo separate pumps are in factemployed in this case, but these are combined in a single device and are actuated by a common shaft which rotates at the same speed as the engine.

ln said drawings:

Fig. 1 is a vertical longitudinal section on the axis of the device, showing only one pump in section. v

Fig. 2 is a vertical cross-section through the axis of a pump, this being the pump which is not shown in section in Fig 1.

Fig. 3 is a horizontal section through the upper casing.

Fig. 4 is a horizontal section throughthe' racks actuating the regulating stop-pieces.

Fig. 5 shows the profiles of the cams.

Fig. 6 is a sectional viewof the fuel admission cock.

1 (Fig. 1) indicates the actuating shaft which is connected with the engine by a coupling device, not shown. Upon the said shaft is secured by means of a key 7 engaging in a key way 7 n, aV sleeve 5 which is provided with a helical slot cooperating with a stud 4. j rllhis latter is mounted upon a bushing 3 secured to a cam shaft 2. A fork 8Jsecured to a rock shaft 8 provides for the lengthwise movement of the sleeve 5'during the running. of the apparatus,- in such manner as to obtaina relative angular displacement of the twol shafts 1 and 2 by means of the helical groove, whereby the moment of the injection may be varled bythe outer lever 45 (Fig. 4) which is secured upon the rock shaft 8".

The pistons 13 of the pump are actuated by the cams 9 mounted on the shaft 2 through the intermediary of the pusher rod 11 slidable in the guiding members 12. Fach piston is slidable in a guiding member 59 and is provided with a return spring 14.

Fach of the fuel suction valves 16 which is guided by a cap 18, is actuated by a cam 10 through the intermediary of a pusher rod 22 slidable in a guiding member 23 and a rod 20 slidable` in a guiding member 21.V The rod 20 is provided with a finger 46 adapted to lift the valve by acting upon an adjustable stop piece 19. The valve is closed by the spring 17 as soon as the camv 10 -permits the pusher rod 22 to fall. 31 indicates the discharge valve through which the liquid fuel is delivered to the atomizer of the engine.

The shafts 1 and 2 are contained in a easing 24 having disposed thereon a casing 25 containing the regulating devices and having disposed thereupon the frame 26 forming the main body of the pump. Upon 'the said frame is secured the upper casing 27. A central pin 28 serves to assemble these various parts by the use of the nuts 29 and 30, the latter being used as an oil filling plug. A fixed stop piece=65, (Fig. 1) secured to the pump body 26 is employed to prevent the piston 13 from leaving its guiding member, upon dismounting t'he apparatus, under the action of the spring 14.

rllie liquid fuel is brought to the pump by means of a three-way cock 32 (Figs. 2 and 6) which provides for the use of two separate fuels, one being employed for starting purposes. rlhe liquid fuel passes through a filter 33 and is admitted to the fuel chamber through a duct 34.A

Upon the guiding members 12, are screwedthe nuts 35 having formed on their periphery suitable gear teethl cooperating with tubular racks 38 (Figs. 2 and 4) in such manner that by actuating the latter, the upper part 36 of the nuts is caused .to approach or to recede from a flange 37 disposed upon each of the pistons 13. Within each of the racks 38 is screwed aring 39, Fig. 4, these rings having respectively a right and lefthand thread and being provided with a central square aperture having respectively slidable therein by easy friction the rods40 having a square cross section. The said rods are secured to an actuating rod 43. Shockabsorbing springs 41 are disposed on either side of the rings 39 and bear upon shoulders is about to be' suddenly moved upwards-for piston,

discharge and injectionby the portion of "the profile 47, 48. From the point 48 to 49 vthere 'is formed a long cylindrical Vportion which maintains the plston in the fixed position at the top of its stroke. During this time the cam 10, Fig. 5, which is here represented in its proper angular position with reference to the cam v9, has now gradually raised the admission valve 16 by the portions 50 to 51, by means of the above-described devices. From the points 49 to 52, the cam 9 will now provide for the descent of the pis- Atom 13 for admission purposes by the action of the spring 14. Upon the descent of the the valve 16, which has been left fully opened after the point 51, will begin to close at 53 and will be entirely closed at 54, the piston 13 being again motionless from 52 to 47. The output is regulated by means of the nuts or movable stop-pieces 35. These arey more or less raised or lowered by screwing or unscrewing the same upon the guiding members 12, thus stopping' the pistons on their downward stroke at any point thereof b the contact between the surfaces 36 and 37 The pusher rods 11 alone will continue upon the descent under the action of the springs 55. This point will be considered in detail hereunder. In this manner all the possible amounts of stroke may be obtained bctween zero and the maximum accorded by the profile of the cam.

The nuts 35 are both controlled at the same time by the above-mentioned racks 38. The use of a double interior spring 41 t0 actuate each of the said racks is to be remarked in connection with the profile of the cams, as will be further set forth. The long cylindrical portion 48, 49 of the cam 9 will be observed. During this entire period, the piston 13 remains entirely raised, and the corresponding nut 35 is altogether relieved. For this reason, the slightest effort will sufiice to move this nut. During the period from 49 to 52,

-' entire 47 and 48, on the contrary, the nut 35 is--or may be according to its heightsubmitted to the effort of the spring 14 which presses together the surfaces 36 and 37. During this hase, admitting that the rod 43 connectedby the yoke 44 with the centrifugal or like governor not shown, has been impelled 'in one or the other direction, the springs 41 will have alone been operative, one being stretched and the other compressed. s Upon the subsequent passage of the portion of the cylindrical profile 48, 49, the springs-41 will now act upon the rack 38 through the medium of the ring 39 in the desired sense. This will afford a much greater sensitiveness for the governor, which is only obliged to overcome the lvery slight force of the springs 41. These s rings' are made very weak, inasmuch as t ey are always called upon to act upon a member which is relieved andk is very easy to move. Itis obvious-that this actlon will only take place ifthe screwthreaded portions 56 of the rings 35 are not of a reversiblenature and are therefore not A subjected to'rotation under the lengthwise pressure of the spring 14, `this being an ab.

solutely essential condition.

The parts 40 having a square cross section and the right and-left hand screwthreads of the rings 39 are provided for the purpose of adjustment. After disconnecting the control member from the yoke 44, the rod 43 is `turned about andthereby effects the rotation of the rings 39 in the racks 38; these latter are however held against rotation by reason of their teeth being in engagement with the nuts 35. The two racks are thus separated or brought together to` a greater or less deree, in order to complete the identical ad- ]ustment of the two stop pieces 35 in the vertical sense with reference of the two stop pieces 35 in the vertical sense with reference to the flange portions 37 of the pistons, this adjustment 'having already been approximately carried out by a suitable location of the engaging point of the vinterengaging teeth. In the example here shown, the rod 44 can only be rotated through half a revolution, which appears to be sufficient, especially if the screwthread of the rings 39 is very fine, but the vadjustment might be carried out upon the rod 43 alone, this being romay be unscre'wed, or a readily removable door may be disposed thereupon, and the said position may be rapidly ascertained by means of a suitable mark which is placed upon the end of the shaft. The rod 43 may then be adjusted by hand in order to bring the two stop-pieces 35 in contact, by means of their surfaces 36, with the flanges 37. The two contacts should take place exactly at the same time if the adjustment is wellcarried out, and this may be observed, and evenv measured if required, by the use ofa guage. through the inspection cover 58, Fig. 1, of the casing 25, the said cover serving likewise for theinsertion of thewrench used to iso - piece secure antenas tighten the piston guide member 59 which also constitutes a packing member.

lt should be observed that this method for adjusting the stop-piece by a simple rotation of the rod 43 is only applicable to the case of an apparatus comprising two pumps. However, the control of all the stop. pieces by means of racks combined with elastic coupling employing double springs, such as 41, 1s applicable to an apparatus comprising any number ot pumps.

llt is to be noted that although the cylindrical portion 48; 49 of the cam 10 is of considerable value as compared with the entire profile, it nevertheless corresponds to a very short period of time in a high speed engine. At' each passage of the remaining portion of the cam, the rack is held in the hired position. lUpon each occurrence of the moment at which the springs 41 are enabled to act, they are obliged to overcome the inertia of the racks 38 andthe nuts 35 which they are required to actuate and which are stationary when acted upon. Tt is thus important that these parts be given as light a weight as ossible. The nut 35 which is subject to t e impact is made preferably ot steel of high strength whereby a very reduced thicmess may be em loyed. The rack is preferably made et an loy of aluminum, and its bore may be disposed in an eccentric position in order that the member shall have? the thin portion situated on lthe side opposite the teeth. This member may likewise be constituted lby an extremely thin tube havthe toothed portion formed thereon by the pressing recess. lu this case, a suitable dp within the said member, and

preferably soldered would be provided with the right or left hand screwthread cooperatin with the rings 39. y

n this device, the long cylindrical portion 48, 49 of the cam 9 is used to very goed advantage trom another stand oint and aside from the question of regu ation. llt has been already remarked that the admission valve 16 .is required to be entirely opened before the commencement of the f downward stroke ot the piston 1t), this being "l eo necessary in order to revent the accumulation of two suction e ects, inasmuch as the valve itself acts asa piston, as in fact the movement ot the valve head increases the internal capacity of the pump. But the conditions ot the opening movement of the valve are not indiiierent. At the beginning of this operation, in fact, the llow section ast the valve seat is extremely small, and

ence the lifting movement should be very `slow and should then gradually increasein speed. This action r uired the use of a considerable length of iftin prole 50, 51

j which constitutes a spira oit increasing pitch,.while the portion 49--52 of the cam 9 'through the a ertures 62. Darin will act as a cus ion for Y held fast at the middle point of the stroke,I

for instance and when the pusher rod l1 which is o erating at tull speed under the edect oft e portion 47, 48 of the cam 1Q enters in contact with the said piston at the upper end of the said pusher rod, there is produced a very marked sound. This sound can however be greatly reduced by the use of the following arrangement. The nut 35 is provided with an .inner chamber 35 and a plurality of apertures 62, and on the other hand the casing 25 is made tight and is hlled with a rather duid oil. ln this case, when the piston is held at a point on its down stroke by the stop piece 36 and the pusher continues its descent under the action ot the sprin 55 (Fig. l), the space now formed in cham er 35n between the corresponding surfaces 460 of the pusher and 6l ot the piston will become lilled with oil which has entered the up stroke, this oi deadening the sound.

The presence oi this oil ol a Huid character and the use oit the closed casing will .likewise have an eheect which is advantageous and prejudicial at the same time-but more advantageous than otherwise-as regards the regulation of the mechanical movement. llt will in fact provide tor a very smooth running ot the mechanical parts, these being kept perfectly clean, and this easy running 1s 'of constant duration, which exerts a :tavorable inuence upon the action ot the governor, as above-stated, but on the contrary, the inertia of the liquid to be displaced must be added to that ot the metal parts set in movement by the action of the springs 4l, and especially of the racks. This drawback may be reduced, not only by the above-indicated use of, duid oil which has been already recommended as adordin an easy friction for the said parts working under light loads, but also by the arrangement oil suitable dow sections at 63, 64 (Fig. l) around the said racks. lt will be noted that a shock is also produced between the surfaces 36 and 37, but this shock, which is here considerably lesshwill likewise be diminished bythe presence of oil.

The use ot the said casin 15 filled with oil makes it necessary to emp oy special precautions to secure the tight working of the piston .13. The fuel must in tact be prevented from entering the casing 25 whence it might enter the casing 24. A suitable disposition is' therefore employed whereby any liquid fuel which may leak through the pack-a lll@ ias

' packing member is provided with a shoulder 66 (Fig. 1) adapted to press an elastic washer 67 against a corresponding shoulder in the pump body 26, and on the other hand the lower end of the guiding member 59 is provided with a second packing member y68 of a more summary description which in the present example is held automatically pressed by the spring 14 itself, by the use of a suitable cap 69. The guide-member 59 is likewise provided at the upperfpart-and -on the interior and exterior belowfth'e packing' member 65, with grooves and ducts such as 70, 71 situated opposite a duct 72 (Fig. 2) formed in the pump body in'such manner as to permit the leaking oil to ow visibly to the exterior into suitable cups such as 73, which may be wiped oleane when required. Th'e use of these recesses or cups .73, which are separate for each pump, will ermit of ascertaining which o the packmg members is leaking.

It will be remarked that an appreciable advantage is aiorded by a complete filling of the casings 24 and 25 with oil and by making the same perfectly oil-ti ht, inasmuch as the liquid fuel which may ave leaked out will no lon r be able to enter the same, and it will be o liged to How to the outside even if the packing member 68 and the packing 67 would be defective. A stuliing box 74 has also been rovided at the end of the shaft 1, and a cu s aped leather 82 on the rod ,43. A stuiling ox, not shown, is also disposed at 75 about the shaft 8, yand to obviate the necessity of a tight working for the guidin members of the rods 20, the upper caslng 2 Iis also made oil-tight and is also filled with oil, the whole being readily filled by the use of the stopper 30 dlsposed at the up er part.

i This latter disposition, comprising t e upper casing filled with oil, acts with reference to the stufling box 76 in the same manner as has already been set forth for the joints 67 and 68.

As concerns the filling with oil, various a ertures of considerable size such as 77 ig. 3) and 78 (Fig. li) are used to afford communication between the various levels, and smaller passages such as 79 (Fig. 3) and 80 (Fig. 4) are provided for the discharge of the air from these di'erent Iportions jif the apparatus. These passages 77 to 80 are not located in the section planes of v Figs. 1 and 2, and have not been yshown for reater clearness. The passage 77 passes t rough themain body 26; the passage 78 transverses the upper wall 'of the casing 24; the passage 80 starts from the casing 24 and ends at the upper part of the casing 25; the

' passage 79 starts from the casing 25 and ends at the upper part of the casing 27.

sary to make use of the double springs 41.' The regulator may be so designed as to exert H its effect upon the nuts 35, evenshould these be under load, bnt rather considerable variations in speed would be necessary in order to obtain the force required to operate the nuts 35 under these'conditions.

Such speed variations, which would be prohibitive 'in the case 4of an electrical enerator group, for in stance, will have no `importance in the case of a motor vehicle. For this latter use, the

governor comprises,Y as is well known, a device which is under the control of the driver for obtaining at will all the speeds below maximum speed.

As above stated, the adjustment of the -point of injection, which is much simpler than that of the output, is obtained by actuating the fork 8 by the lever 45 which is operated by hand. It is obvious that this device would also .be acted upon a centriugal or like governor, and in this caseit Awould be possible to replace all the lead adjustment mechanism as above described by an automatic mechanism working according to the speed, this being of the well known type such as is used for a like pur` pose upon magnetos for internal combustion en ines with variable speed. Y

t is understood .that this invention is not limited to the constructional details berein- `before set forth.

Having now described my inventlon, what I claim as new and deslre to secure by Letters Patent is:

1. A pump for injecting liquid internal combustion engines comprising a pump body,- a piston movable in said pump body, a rotary driving shaft, a cam on said shaft for actuating the iston in its discharge stroke, a spring or actuating the piston in its suction stroke and an adjustafegi frble stop member for limiting the suction stroke of the piston, the cam' having its maximum diametery over a portion extending at least about half the circumference whereby the piston is lifted and the adjustable stop member is relievedfor a considerable part ofi each revolution of the cam.

2. A pump for injecting liquid fuel for internal combustion engines comprising a pump body, a piston movable in said pump body, a rotary driving shaft, a cam on said shaft -for actuating the iston in its discharge stroke, a spring or actuating the piston in its suction strpke, a supporting member, a nut screwed upon said su porting member and forming an adjustab e stop for limiting the suction stroke of the in a rack in engagement with gear teeth ormedi pump body,

on said nut and means for rack. l

3. A pump for injecting liquid fuel tor internal combustion engines comprising a a piston movable in said pump body, a rotary driving shaft, a cam on said shaft for actuating the piston in its discharge stroke, a spring for actuating the piston in its suction stroke, a supporting member, a nut screwed upon said support-- ing member and forming an adjustable stop for limiting the suction stroke of the piston, a rack in engagement with gear teeth formed on the nut, control means for operating said rack and springs adording a yielding connection between said rack and the control means.

d. A pump apparatus for injecting liquid fuel for internal combustion engines, comprising two pump bodies, two pistons movable in said pump bodies respectively, a rooperating said tary driving sha-ft, .cams on said shaft for actuating the pistons in their discharge stroke, respectively, springs for actuating the pistons in their suction stroke, respectively, supporting members, nuts screwed upon said supporting members respectively and forming adjustable stops for` limiting the suction stroke of the pistons, racks respectively in engagement with gear teeth formed on said nuts, screwthreaded rings screwed in said vracks, respectively, a control rod having parts of polygonal cross section which extend through said screwthreaded rings, and springs on both sides of said screwthreaded "rings and bearing upon shoulders on said control rod.

5. A pump for injecting liquid fuel for internal combustion engines comprising a pump body having a pump chamber therein a piston movable in said pump chamber, `a lower casing below said pump body, a rotary driving shaft mounted in said lower casing, a cam on said shaft, a pusher rod operatively connecting the piston and the cam, guiding means for said pusher rod, an intermediate casing containing said guiding means, a spring for actuating the piston in its `suction stroke, said spring being arranged in said intermediate casin a uel chamber in the pump body above t e pump chamber and an upper casing on the pump body above said ituel chamber, said upper,

imtermediate casing containing said intermediate, and lower casings being filled with oil, and means adording a communication between said casings.

6. A pump lor injecting liquid fuel lor internal combustion engines comprising` a pump body having a pump chamber therein a piston movable in said pump chamber, a lower casing below said pump body, a rotary` driving shaft mounted in said lower casing, a cam on said shalt, a pusher rod operatively connecting the piston and the cam, guiding means for said pusher rod, an idine7 means, a spring tor actuatin the plston iii its suction stroke, said spring being arranged in said vintermediate casing, a fuel chamber in the pump body above the pump chamber and an upper casing on the pump body above said `t'uel chamber, said up er intermediate and lower casings being nlA ed with oil, means adording a communication between said casings, means forming an oil chamber in the intermediate casing around the point of impact between the pusher rod and the piston and means atlording a restricted communication between the said oil chamber and the intermediate casin A pump for injecting liquid i'uel for internal combustion engines, comprising a pump body having a pump chamber therein, a piston movable in said pump chamber,

a lower casing below said pump body, a rotary driving shaft mounted in said lower casing, a cam on said operatively connecting cam, guiding means for said pusher rod, an intermediate casing containing said guiding means, a spring tor actuating the piston in its suction stroke, said spring being arranged in said intermediate casing, a fuel chamber in the pump body above the pump chamber and an body above said jr'uel chamber, said upper intermediate and lower casings being lled with oil and means ahiordmg a communicathe piston and the tion between saidi casings, ducts being provided in the side the piston. Y

ln testimony whereof l have signed my name to this specicetion,

EUGNE HENRI TARTRMS.

l .pump body to direct to the out; fuel which may leali around the upper casing on the pump I shalt, a pusher rod i v 

